Vexillation Fort

Smaller fortresses, known as vexillation fortresses, is a term applied to large rectangular Roman forts, with rounded corners of between 6.4 ha and 12.0 ha, which were occupied on a temporary basis by campaigning forces of between 2500 and 4000 legionary or auxiliary troops.

They were constructed as part of Roman military strategy immediately after the conquest in AD 43, mostly in the south of England, when the army had not yet established the boundaries of its occupation, and continued to be involved in campaigns to increase and establish its control. They could have been designed to provide winter quarters for half‑legions or provided accommodation for a number of brigaded auxiliary units during the original conquest phase of Britain. All sites were probably abandoned by about AD 90.

Defined by a single rampart of earth or turf, usually revetted at the front and rear with turf or timber and surrounded by one or more outer ditches. Such forts have a characteristically rectangular outline with rounded corners. Originally a breastwork and a wall walk of timber would have crowned the rampart, possibly with corner and interval towers.

Most contain evidence of internal buildings because although temporary in the overall scheme of things most were in fact occupied for several seasons. They are frequently recognized through aerial photography.

Locations of Vexillation Forts in Roman Britain